Packaging structure and packaging method

Abstract

A package and a packaging method are provided. The package includes a chip unit, a protective cover plate, and an adhesive unit. The chip unit has a first surface, where the first surface includes a device region. The protective cover plate has a second surface opposite to the first surface of the chip unit. The adhesive unit is located between the first surface of the chip unit and the second surface of the protective cover plate and is configured to bond the chip unit with the protective cover plate. The adhesive unit includes a first region and a second region having different viscosities.

1 . A package, comprising:
 a chip unit having a first surface, wherein the first surface comprises a device region;   a protective cover plate having a second surface opposite to the first surface of the chip unit; and   an adhesive unit located between the first surface of the chip unit and the second surface of the protective cover plate and configured to bond the chip unit with the protective cover plate, wherein the adhesive unit comprises a first region and a second region having different viscosities.   
     
     
         2 . The package according to  claim 1 , wherein the viscosity of the first region is less than the viscosity of the second region. 
     
     
         3 - 4 . (canceled) 
     
     
         5 . The package according to  claim 1 , wherein the adhesive unit comprises a first adhesive layer, with the first region and the second region being in the first adhesive layer. 
     
     
         6 . The package according to  claim 2 , wherein the adhesive unit comprises:
 a first adhesive layer;   a second adhesive layer; and   a transparent base located between the first adhesive layer and the second adhesive layer, wherein   the first adhesive layer is located between the transparent base and the second surface of the protective cover plate, and the second adhesive layer is located between the transparent base and the first surface of the chip unit.   
     
     
         7 . The package according to  claim 6 , wherein the first region and the second region are located in the first adhesive layer. 
     
     
         8 . The package according to  claim 6 , wherein the first region of the adhesive unit is the first adhesive layer, and the second region of the adhesive unit is the second adhesive layer. 
     
     
         9 . The package according to  claim 1 , further comprising: a support structure, wherein
 the support structure is located between the first surface of the chip unit and the adhesive unit, with the device region being located in a groove surrounded by the support structure and the adhesive unit; or   the support structure is located between the first surface of the chip unit and the adhesive unit, and the support structure is bonded with the first surface of the chip unit by an adhesive layer, with the device region being located in a groove surrounded by the support structure and the adhesive unit.   
     
     
         10 . (canceled) 
     
     
         11 . A packaging method, comprising:
 providing a chip unit having a first surface, wherein the first surface comprises a device region;   providing a protective cover plate having a second surface; and   forming an adhesive unit for bonding the first surface of the chip unit with the second surface of the protective cover plate, wherein   the adhesive unit comprises a first region and a second region having different viscosities.   
     
     
         12 . The packaging method according to  claim 11 , wherein the forming an adhesive unit for bonding the first surface of the chip unit with the second surface of the protective cover plate comprises:
 forming an adhesive unit having a variable viscosity and bonding the first surface of the chip unit with the second surface of the protective cover plate; and   processing the adhesive unit to form the first region and the second region having different viscosities in the adhesive unit.   
     
     
         13 . The packaging method according to  claim 12 , wherein the viscosity of the first region is less than the viscosity of the second region. 
     
     
         14 - 15 . (canceled) 
     
     
         16 . The packaging method according to  claim 13 , wherein the adhesive unit comprises a first adhesive layer. 
     
     
         17 . The packaging method according to  claim 13 , wherein the adhesive unit comprises:
 a first adhesive layer;   a second adhesive layer; and   a transparent base located between the first adhesive layer and the second adhesive layer, wherein   the first adhesive layer is located between the transparent base and the second surface of the protective cover plate, and the second adhesive layer is located between the transparent base and the first surface of the chip unit.   
     
     
         18 . The packaging method according to  claim 16 , wherein the processing the adhesive unit to form the first region and the second region having different viscosities in the adhesive unit comprises:
 processing the first adhesive layer to form the first region and the second region in the first adhesive layer.   
     
     
         19 . The packaging method according to  claim 17 , wherein the processing the adhesive unit to form the first region and the second region having different viscosities in the adhesive unit comprises:
 processing the first adhesive layer to decrease a viscosity of the first adhesive layer, wherein the first adhesive layer serves as the first region of the adhesive unit, and the second adhesive layer serves as the second region of the adhesive unit.   
     
     
         20 . The packaging method according to  claim 18 , wherein the first adhesive layer is made of a photosensitive adhesive having a first debonding wavelength, and processing the first adhesive layer to form the first region and the second region having different viscosities in the first adhesive layer comprises:
 irradiating a portion of the first adhesive layer with a light source having the first debonding wavelength, wherein a viscosity of the portion of the first adhesive layer irradiated by the light source is decreased to form the first region, and a viscosity of a portion of the first adhesive layer not irradiated by the light source is not changed to form the second region.   
     
     
         21 . The packaging method according to  claim 19 , wherein the first adhesive layer is made of a photosensitive adhesive having a first debonding wavelength, the second adhesive layer is made of a photosensitive adhesive having a second debonding wavelength not equal to the first debonding wavelength, and the processing the adhesive unit to form the first region and the second region having different viscosities in the adhesive unit comprises:
 irradiating the adhesive unit with a light source having the first debonding wavelength, wherein the viscosity of the first adhesive layer is decreased to be zero to form the first region, and a viscosity of the second adhesive layer is not changed to form the second region.   
     
     
         22 . The packaging method according to  claim 20 , wherein the light source is a laser light source or a surface light source,
 in a case that the light source is the laser light source, the irradiating a portion of the first adhesive layer comprises:
 irradiating a portion of a third surface of the protective cover plate with the laser light source along a predetermined path, wherein the third surface is opposite to the second surface; and 
   in a case that the light source is the surface light source, the irradiating a portion of the first adhesive layer comprises:
 forming a patterned light shielding layer on a third surface of the protective cover plate, with the patterned light shielding layer exposing a portion of the protective cover plate, wherein the third surface is opposite to the second surface; and 
 irradiating the third surface with the surface light source. 
   
     
     
         23 - 24 . (canceled) 
     
     
         25 . The packaging method according to  claim 18 , wherein the first adhesive layer is made of a hot melt adhesive, and processing the first adhesive layer to form the first region and the second region having different viscosities in the first adhesive layer comprises:
 irradiating a portion of the first adhesive layer by using laser or ultrasound, wherein a viscosity of the region irradiated is decreased to form the first region, and a viscosity of a portion of the first adhesive layer not irradiated is not changed to form the second region.   
     
     
         26 . The packaging method according to  claim 12 , wherein the forming an adhesive unit having a variable viscosity and bonding the first surface of the chip unit with the second surface of the protective cover plate comprises:
 forming an adhesive unit on the second surface of the protective cover plate and bonding the first surface of the chip unit with the adhesive unit; or   forming an adhesive unit on the first surface of the chip unit and bonding the second surface of the protective cover plate with the adhesive unit.   
     
     
         27 . The packaging method according to  claim 12 , wherein the forming an adhesive unit having a variable viscosity and bonding the first surface of the chip unit with the second surface of the protective cover plate comprises:
 forming a support structure on the first surface of the chip unit, with the support structure being located outside the device region;   forming an adhesive unit having a variable viscosity on the second surface of the protective cover plate; and   bonding the support structure with the adhesive unit.   
     
     
         28 . The packaging method according to  claim 12 , wherein the forming an adhesive unit having a variable viscosity and bonding the first surface of the chip unit with the second surface of the protective cover plate comprises:
 forming an adhesive unit on the protective cover plate;   forming a support structure on the adhesive unit; and   bonding the support structure with the first surface of the chip unit by an adhesive layer, with the device region being located in a groove surrounded by the support structure and a surface of the adhesive unit.   
     
     
         29 . The packaging method according to  claim 12 , wherein the chip unit is on a to-be-packaged wafer comprising a plurality of chip units and a cutting trench formed between adjacent chip units among the plurality of chip units;
 the chip unit further comprises contact pads located on the first surface and outside the device region; and   after bonding the first surface of the chip unit with the adhesive unit and before processing the adhesive unit, the package method further comprises:
 thinning the to-be-packaged wafer on a fourth surface of the to-be-packaged wafer, wherein the fourth surface of the to-be-packaged wafer is opposite to the first surface; 
 etching the to-be-packaged wafer on the fourth surface of the to-be-packaged wafer to form through holes, wherein each of the through holes exposes one of the contact pads; 
 forming an insulation layer on the fourth surface of the to-be-packaged wafer and sidewalls of the through holes; 
 forming a metal layer connected with the contact pads on the insulation layer; 
 forming a solder mask on the metal layer and the insulation layer, wherein the solder mask is provided with openings to expose a portion of the metal layer; 
 forming solder bumps on the solder mask, wherein each of the solder bumps fills one of the openings; and 
 cutting the to-be-packaged wafer, the adhesive unit and the protective cover plate along the cutting trench to form a plurality of separate packages.